Monday Poster Sessions, October 29, 2006

HCV Therapy: Pre-clinical and Early Clinical Development

 

 

927. Current status of subjects receiving Peg-Interferon-Alfa-2a (Peg-IFN) and Ribavirin (RBV) Follow-on therapy after 28-Day treatment with the hepatitis C protease inhibitor TELAPREVIR (VX-950), Peg-IFN AND RBV. 

M. Rodriguez-Torres; E. Lawitz; A. Muir; J. Keane; T. Kieffer; L. McNair; J. G. McHutchison

 

Purpose:

Telaprevir (VX-950) is an orally administered, highly selective peptidomimetic inhibitor of the Hepatitis C virus (HCV) NS3-4A protease. In previously reported Phase 1b studies, telaprevir was well tolerated alone and with peginterferon-alfa-2a (Peg-IFN) for 14 days, and the marked antiviral effects of telaprevir are increased with the addition of Peg-IFN. This study was designed to assess the safety of telaprevir when given in combination with Peg-IFN and ribavirin (RBV) and to evaluate the antiviral response during 28 days of dosing. Here we report patient status during ongoing post-study follow-on therapy.

 

Methods:

The VX05-950-102 clinical study included 12 treatment-naïve patients infected with genotype 1. All subjects received telaprevir (750 mg q8h), Peg-IFN (180 µg weekly), and RBV (1000 or 1200 mg daily). At the completion of the 28 days, patients began off-study follow-on standard therapy with Peg-IFN/RBV.

 

Results:

At 24 weeks after the start of Peg-IFN-2a/RBV:

·        9 subjects had undetectable HCV RNA

·        2 subjects had detectable HCV RNA

·        1 subject was lost to follow-up

 

Conclusions:

·        2/12 subjects had detectable HCV RNA at the end of the study dosing and continued Peg-IFN-2a/RBV therapy

·        9/11 subjects treated initially with telaprevir in combination with Peg-IFN-2a and RBV who continued Peg-IFN-2a/RBV, maintained undetectable HCV RNA through week 24 in the off-study Peg-IFN/RBV treatment period.

o       one subject lost to follow-up

·        Viral sequencing suggests that:

o       Variants are detected transiently early in treatment but remained undetectable during follow-on treatment

o       In the 2 patients with breakthrough, detection of both WT and R155K suggest that breakthrough may be related to a poor response to Peg-IFN-2a/RBV

o       It will be important to evaluate longer durations of telaprevir treatment

·        The safety and efficacy of a telaprevir-based treatment in longer regimens is currently being evaluated in Phase 2 studies (PROVE1 AND PROVE2).


928. In vitro antiviral interactions of a novel HCV inhibitor R1479 with interferon α-2a, ribavirin and other HCV inhibitors. 

W. Jiang; S. Chiu; S. Ali; M. Chapman; C. Daniel; T. Kretz; N. Cammack; J. Symons; K. Klumpp

 

Introduction:

R1479 (4’-azido-cytidine) is a potent, specific inhibitor of the HCV subgenomic replicon replication by targeting HCV polymerase mediated RNA synthesis. R1626, a prodrug of R1479, has shown promising anti-HCV activity in a Phase I clinical study in chronically HCV infected patients. Future clinical studies will assess safety and efficacy of R1626 in combination with other antiviral agents.

 

Results:

In the present study, we investigated the in vitro antiviral interactions of R1479 with other HCV replication inhibitors using the HCV subgenomic replicon system. Huh-7 cells containing HCV replicon were treated with a dose range of R1479 in a checkerboard, pair-wise manner with a dose range of either IFN α-2a, ribavirin, 2’-fluoro-2’-C-methylcytidine (PSI-6130), 2’-C-methylcytidine (NM107), the non-nucleoside inhibitors thiophene–2 carboxylic acid and benzo-1,2,4-thiadiazine, and the macrocyclic tripeptide HCV serine protease inhibitor (BILN2061). The antiviral interaction of each drug-combination was assessed using a three-dimensional response surface approach based on the Bliss independence theory (MacSynergy II) or the Greco model based on the Loewe additivity theory. Analysis using both models indicated that R1479 exerted moderate synergistic effects when combined with either IFN α-2a or ribavirin with no associated increase in cellular toxicity.

 

Conclusions:

Combinations of R1479 with other HCV Polymerase inhibitors PS1-6130, 2’-C-Me-C, a palm-binding NM1, and a HCV serine protease BILN 2061 demonstrated additive effects. No antagonistic effects were observed with any of the combinations within the range of concentrations tested.

 

 

929. Development of a universal T-cell vaccine candidate for hepatitis C applicable to the majority of human HLA types and HCV genotypes. 

V. Goossens; I. Borghmans; A. Schittecatte; A. Van der Aa; G. Verheyden; S. Southwood; C. Dahlberg; D. McKinney; M. Newman; J. Pletinckx; I. Lasters; J. Desmet; G. Maertens; M. Buyse

 

Background:

Successful viral clearance has been shown to be associated with strong and multispecific CD8+ T-cell responses accompanied by strong CD4+ T-cell responses. A candidate polyepitope therapeutic T-cell vaccine that is able to induce both potent CD8+ and CD4+ specific T-cell responses could ultimately lead to viral clearance. Such a vaccine should be applicable to the majority of infections, taking human HLA as well as HCV genotype diversity into account.

 

Methods:

HCV-derived CTL epitopes for the most prominent HLA-A, -B, and -C alleles were identified using algorithms developed by Pharmexa-Epimmune (San Diego, CA), Algonomics (Ghent, Belgium), and publicly available algorithms. Further selection was made based on in vitro binding affinity of the peptides. A subset of good binders was further evaluated for immunogenicity in human HLA transgenic mice. A single immunization with CTL peptide pools, together with the common PADRE HTL epitope emulsified in IFA, was performed and 14 days later, CD8+ spleen cells were isolated and evaluated for peptide specificity using a direct ex-vivo IFNγ ELISPOT. In parallel, predicted HCV-derived HTL epitopes were evaluated for their in vitro binding to different DRB1* alleles and for their immunogenicity in DRB1*0401 transgenic mice.

 

Results and discussion:

Several medium (Ki or IC50 <500 nM) and high (Ki or IC50 < 50 nM) affinity binding peptides were identified for all selected HLA -A, -B and -C alleles. Cross-reactivity to different HLA loci was demonstrated for some of the peptides.

 

Peptides binding to HLA A*0201, A*1101, A*2402 or B*0702 alleles with medium or high affinity were selected for evaluation of CTL induction in the respective HLA transgenic mice. Based on IFNγ ELISPOT several highly immunogenic epitopes were identified. Similarly, a set of HTL epitopes was identified showing promiscuous binding to the DRB1* alleles. Immunogenicity testing in DRB1*0401 transgenic mice revealed that in vitro affinity was a strong predictor of significant immunological responses. Population coverage calculations showed that the selected set of CTL and HTL epitopes could provide recognition of at least 4 CTL and 3 HTL epitopes in an HCV genotype 1-infected subject irrespective of HLA type.

 

Conclusion:

A pool of HCV-derived CTL and HTL epitopes were identified that show excellent affinity and immunogenicity. Based on the HLA and HCV genotype cross-reactivity, more than 45 epitopes were selected that could form the basis for the development of a universal T-cell vaccine candidate for HCV.

 

931. In Vitro Resistance Studies of AG-021541, a Novel Nonnucleoside Inhibitor of the Hepatitis C Virus RNA-dependent RNA Polymerase. 

S. T. Shi; K. J. Herlihy; J. Gonzalez; A. K. Patick; R. Duggal

 

Discussion:

A novel class of nonnucleoside HCV polymerase inhibitors characterized by a dihydropyrone core was identified by high throughput screening. Crystallographical studies of these compounds in complex with the polymerase identified an allosteric binding site close to the junction of the thumb and finger domains, approximately 30 Å away from the enzyme’s catalytic center. AG-021541, a representative compound from this series, displayed measurable in vitro antiviral activity against the HCV subgenomic replicon with a mean EC50 value of 2.9 µM. To identify mutations conferring in vitro resistance to AG-021541, resistance selection was carried out using HCV replicon cells harboring a genotype 1b subgenomic reporter replicon either by serial passages in increasing concentrations of AG-021541 or by direct colony formation at fixed concentrations of the compound. Both population and clonal sequencing were performed to identify genotypic changes in AG-021541-resistant cell lines. We identified several amino acid substitutions in the inhibitor-binding region of the polymerase, including M423T, M423V, and V494A. The most predominant mutation, M423T, conferred an 87-fold reduction in susceptibility to AG-021541 but no change in susceptibility to interferon. AG-021541-resistance replicon cell lines provide a valuable tool for specificity and mechanism of action studies of dihydropyrone polymerase inhibitors. The clinical relevance of in vitro resistance to HCV polymerase inhibitors remains to be investigated.

 

Conclusions:

·        In vitro resistance studies of AG 021541 by either passages or instant colony formation using the replicon cells identified amino acid changes at the thumb-base allosteric site

·        The most predominant mutation, M423T, conferred an 87-fold reduction in susceptibility to AG-021541, but no change in susceptibility to IFN

·        Introduction of M423T, M423V or V494A into the wild-type replicon resulted in reduction replication fitness and resistance to AG-021541 and structurally related to compounds

·        In vitro resistance studies are useful tools for determining the specificity and target/MOA of anti-HCV compounds.

·        Resistance mutations identified in the replication system may have future clinical implications.

 

932. Assessment of the Pharmacological Activity of PEGylated Recombinant Interleukin-29 (PEG-rIL-29) in Cynomolgus Monkeys. 

J. A. Freeman; J. Heffernan; K. Klucher; P. Sivakumar; S. Pederson; J. Visich; P. Rafael; M. Rogge

 

Background:

Interleukin-29 belongs to a family of Class II cytokines and binds to a heterodimeric receptor consisting of the unique IL-28R alpha chain and the common IL-10R beta chain. Binding of IL-29 to this receptor activates the JAK/STAT pathway in a similar fashion to interferon alpha, and has been shown to induce intracellular antiviral responses in vitro. The Type I interferon receptor is expressed by a wide variety of cell types; however, the IL-29 receptor is expressed by only a subset of these cell types. We have investigated whether the differences in the pattern of receptor expression result in pharmacological differences between interferon alpha and IL-29.

 

Methods:

The in vivo activity of a PEGylated form of IL-29 (PEG-rIL-29) was evaluated in cynomolgus monkeys. Pharmacological responses were assessed following either a single or three (every-other day dosing) intravenous doses of 0.03, 0.3, or 3.0 mg/kg PEG-rIL-29. As controls, monkeys were also dosed with vehicle or 1x107 IU/kg interferon alpha 2a. In vivo response to dosing were assessed by quantifying changes in circulating neopterin, 2’5’-oligoadenylate synthetase (OAS) activity, and beta-2 microglobulin. Responses were also assessed by analyzing changes in the expression of the interferon-stimulated genes, MxA and PkR, and in OAS activity within peripheral blood leukocytes (PBLs) and liver biopsy samples.

 

Results:

Dosing with PEG-rIL-29 resulted in an induction in the expression of MxA and PkR in liver biopsy samples taken four hours after dosing, and in an elevation in intracellular OAS activity in liver biopsy samples taken 48 hours after dosing. A similar induction of these markers was observed across all dose levels. Furthermore, the induction of these markers by PEG-rIL-29 was largely equivalent to that by interferon alpha. Consistent with the differential expression pattern of the IL-29 receptor, MxA and PkR expression and OAS activity was induced in PBLs by interferon alpha but not by PEG-rIL-29. Similarly, plasma OAS, serum neopterin, and serum beta-2 microglobulin were elevated by interferon alpha, whereas only serum beta-2 microglobulin was induced by PEG-rIL-29.

 

Conclusions:

·        Localization of PEG-rlL-29 activity appears to be more restricted than that of IFN-a

·        No overt changes in measured immunological parameters observed following dosing with PEG-rlL-29

·        Serum B2M is a relevant circulating marker of PEG-rlL-29 activity that may be monitored in subsequent nonclinical studies

 

933. In Vitro Synergistic Antiviral Activity of ITMN-191, an Orally Active Inhibitor of the Hepatitis C Virus (HCV) NS3/4A Protease, in Combination with PEG-Interferon Alfa-2a. 

H. Tan; S. D. Seiwert; L. M. Blatt

 

Purpose:

ITMN-191 is a highly potent, orally absorbed inhibitor of the NS3/4A protease that accumulates in the liver of rats and cynomolgus monkeys at levels suggestive of human efficacy. This compound is currently undergoing preclinical development. The objective of this study was to evaluate the in vitro antiviral activity of ITMN-191 in combination with peginterferon alfa-2a (PEG-IFN alfa-2a).

 

Methods:

Two replicon systems were used for anti-HCV drug-drug interaction study: an HCV genotype-1b replicon (K2040) and a derivative of K2040 with reduced sensitivity to ITMN-191 (R191M320). Drug-drug interaction data were analyzed by the Loewe additivity model and the Bliss independence drug interaction model.

 

Results:

The combination of ITMN-191 and PEG-IFN alfa-2a synergistically inhibited HCV RNA replication in Huh7 cells. Analysis of fixed dose ratios by the Loewe additivity model showed that combination of the two drugs yielded combination index (CI) values indicative of synergy at EC50, EC75 and EC90 (0.3, 0.4 and 0.4, respectively) and isobologram analysis supported synergistic interaction. The drug reduction index (DRI) values were >1, suggesting a potential clinical benefit when ITMN-191 is administered in combination with PEG-IFN alfa-2a. Analysis of variable ratio drug combinations by the Bliss independence model indicated that the synergy volumes observed in ITMN-191 combinations were significant (>50 uM2). Peak synergy volumes occurred at low concentrations, all of which may be therapeutically relevant. The extent of synergy observed by either method is quantitatively larger than that observed for the experimental HCV protease inhibitors VX-950 and SCH 503034. Importantly, the human minimum plasma concentration (Cmin) of PEG-IFN alfa-2a greatly improved ITMN-191 potency in a replicon fully sensitive to ITMN-191 and in a replicon with reduced sensitivity to ITMN-191. Additionally, the replicon with reduced sensitivity to ITMN-191 was hypersensitive to PEG-IFN alfa-2a relative to the parental replicon (>10 fold).

 

Conclusions:

·        ITMN-191 and Peg-INF-a-2a demonstrated strong antiviral synergy by multiple analyses

·        When used in combination, reduced doses of both agents produce antiviral effects similar higher doses of each agent when used individually

·        At its minimal plasma concentration, Peg-IFN-a-2a greatly enhances the potency of ITMN-191

·        Clinical exploration of the combined antiviral effects of these two agents is warranted

 

934. Preclinical Evaluation of SCY-635, a Cyclophilin Inhibitor with Potent anti-HCV Activity. 

D. R. HOUCK; S. Hopkins

 

Background:

Cyclosporine A (CsA) is known to inhibit HCV replication in vitro and appears to have a therapeutic effect on clinical HCV infection. Recent studies indicate that it acts through inhibition of the human protein cyclophilin. CsA and other members of this natural product family cannot be used as antiviral therapeutics because they have narrow therapeutic indexes due to dose limiting immune, renal and cardiovascular toxicities. In this work we evaluated a non-immunosuppressive cyclophilin inhibitor, SCY-635, as potential clinical candidate for anti-HCV therapy.

 

Methods:

SCY-635 was evaluated for antiviral activity, cytotoxicity, immunosuppression, cyclophilin inhibition, and bioavailability. The compound was tested in the HCV Replicon in Huh7 cells and against BVDV in MDBK cells. Immunosuppression and cyclophilin inhibition were determined in murine-mixed-lymphocyte reaction (MLR) and peptidyl-prolyl-isomerase inhibition assay, respectively. In vitro ADME properties such as microsomal stability were also examined. Pharmacokinetic parameters were determined after single dose in monkeys.

 

Results:

Compared to cyclosporin, SCY-635 had potent (2 nM)affinity for cyclophilin A, 2) had improved anti-HCV activity, 3) was >100-fold less active in the MLR, and 4) was less cytotoxic. Using both the luciferase and RNA endpoints, SCY-635 potently inhibited HCV replication in replicon cells. There was a dose-dependent reduction of HCV RNA at 24, 48, 72 and 120 h incubation periods. Drug-combination experiments demonstrate that SCY-635 is additive to synergistic with IFN-α in the replicon cells. SCY-635 also inhibited the viral replication in the BVDV assay. SCY-635 is much-more slowly metabolized in human microsomes than cyclosporin A. In vivo pharmacokinetic studies demonstrate approximately 50% bioavailability, providing blood levels of drug well in excess of the in vitro IC50 for HCV replicon.

 

Conclusion:

·        SCY-635, a soluble analog of CsA, binds and inhibits cyclophilin A and cyclophilin B

·        SCY-635 suppresses in vitro HCV replication by >95% at sub-µM concentrations

·        Pharmacokinetic data demonstrate that SCY-635 concentrations are well above the antiviral IC90

·        In vitro drug-combination studies suggest SCY-635 is compatible for use with IFN- and ribavirin

·        SCY-635 is a clinical candidate for therapy of HCV infected patients

 


935. Robust Suppression of Viral Replication by a Nucleoside Polymerase Inhibitor in Chimpanzees Infected with Hepatitis C Virus . 

S. S. Carroll; M. Davies; L. Handt; K. Koeplinger; R. Zhang; S. Ludmerer; M. MacCoss; D. Hazuda; D. Olsen

 

Purpose:

to evaluate the antiviral efficacy of administration of a nucleoside polymerase inhibitor to hepatitis C virus (HCV) infected chimpanzees.

 

Purpose:

to evaluate the antiviral efficacy of administration of a nucleoside polymerase inhibitor to hepatitis C virus (HCV) infected chimpanzees.

 

Background:

Efforts to develop novel therapies to treat HCV infection that enhance both efficacy and tolerability over existing therapies have focused on direct antiviral agents targeting the virally encoded RNA-dependent RNA polymerase, NS5B, and protease, NS3/4A. Previously, we have shown that a nucleoside analog inhibitor of the NS5B RNA polymerase potently inhibits HCV RNA replication in the bicistronic replicon assay with an EC50 of 0.3 micromolar.

 

Methods:

The nucleoside analog was administered once daily to chronically infected chimpanzees by either oral or intravenous routes at different dose levels, and for different durations. Periodically blood samples were withdrawn, and plasma viral titers were determined using the Versant bDNA (Bayer), HCV Taqman (Roche), or transcription mediated amplification (Bayer) assays.

 

Results:

The nucleoside analog can profoundly suppress viral replication in chimpanzees chronically infected with HCV. Once daily administration of the compound resulted in a rapid, dose-dependent decrease in plasma viral RNA. At the highest dose evaluated, viral RNA levels in plasma decreased during dosing to levels below the limit of quantitation of the Taqman assay, representing a ≥5 log decrease in plasma viremia. Longer term dosing resulted in substantial decreases in viral load and no rebound during dosing was evident.

 

Conclusions:

·        IV and oral dosing of 7-Deaza-2’-C-methyl-adenosine to HCV-infected chimpanzees result in significant reductions in viral load.

o       >5 log reduction in viral load (2 mpk IV)

o       No rebound during dosing

o       Delay in rebound after end of extended dosing

·        Resistant viral variants at S282 are detected after dosing ends as virus starts to rebound

o       Variants not detected in samples from later time

 


936. Viral Dynamics Study with HCV NS3-4A Protease Inhibitor MP-424/VX-950 in Human-Chimeric Liver Mouse Model for Hepatitis C Virus Infection. 

N. Kamiya; E. Iwao; N. Hiraga; M. Imamura; S. Takahashi; K. Chayama

 

Discussion:

As a small animal model for hepatitis C virus (HCV) infection, several teams are investigating homozygous urokinase plasminogen activator (uPA)-SCID mice transplanted with human hepatocytes. This model is expected to contribute to the evaluation of antiviral therapy whereas there has been less information about viral kinetics under a drug treatment.

 

Using more than thirty uPA-SCID mice where more than half of the liver was repopulated by human hepatocytes, we investigated viral kinetics in this animal model treated with the HCV NS3-4A protease inhibitors, MP-424/VX-950 and BILN 2061. Repopulation index of human hepatocyte in the liver from an uPA-SCID mouse was estimated by human serum albumin (hAlb) concentration in blood. After intravenous infection with HCV genotype 1b, high viral load (>106 copies/mL) was achieved among most animals and plateaued within 6 weeks. The viremia persisted throughout their lives in most animals up to 28 weeks. After the infection, hAlb titer tended to decline slightly and slowly and some positive correlation with HCV titer in serum could be observed especially in a later phase. Oral administration of the HCV NS3-4A protease inhibitors could reduce viral load in this mouse model, and the titer restituted after withdrawal of the drugs. Therefore, the same animals were used to evaluate a different regimen for several independent periods. In the preliminary experiment, twice daily administration of MP-424/VX-950 formulation for 7 days resulted in about half log10 decrease in HCV load, while the same animals re-treated with it three times daily for 3 days showed nearly 1 log10 decrease. This result might suggest the importance of maintaining trough concentration of the drug to show the efficacy in this mouse model. When sufficient trough concentration of MP-424/VX-950 could be achieved, rapid and linear log decrease in HCV RNA titer in serum was observed within the first 12 hrs (≈2 log10) and the mean slope was estimated as 0.15 log10 copies/hr, which might be equivalent to the rate of initial phase decline observed in hepatitis C genotype 1 patients treated with VX-950/MP-424. When MP-424/VX-950 improved formulation or BILN 2061 in solution was administrated orally twice daily, 2-3 log10 reduction of viral load was also observed within 2 days. VX-950/MP-424 and BILN 2061 were demonstrated high and very rapid reduction in serum viral load in their proof-of-concept clinical studies.

 

Conclusion

·        MP-424 suppressed the replication of IFN-NR-derived HCV genotype 1b virus production in vivo in chimeric SCID-uPA mice

·        An early and rapid reduction in viral load was observed in the SCID-UpA mouse model, similar to that observed in humans

·        Using elder mice with high viral, bi- and tri-phasic clearance patterns could be observed, similar to what has been observed in humans

 


937. Induction Of Resistance By A Novel Class Of Compounds Active Against Hepatitis C Virus With No Cross-Resistance To NS3 Protease And NS5B Polymerase Inhibitors . 

W. Yang; Y. Zhao; J. Fabrycki; X. Hou; X. Nie; Y. Sun; A. Phadke; A. Agarwal; M. Deshpande; M. Huang

 

Background and aims:

We have discovered a novel class of compounds active against HCV. The lead compound in the series, ACH-806, is a potent and specific inhibitor of HCV. Mechanism of action studies revealed that inhibition of HCV occurs via blocking of functional replication complex formation. Resistance induction studies were conducted to identify the target of these novel inhibitors, and to determine cross- resistance profile with other classes of inhibitors.

 

Methods and results:

Resistance induction studies were performed using compounds in ACH-806 series. Several clones emerged after addition of the inhibitor and G418 to Huh-7 cells containing stably transfected HCV replicon at frequency and duration similar to that observed with other classes of HCV specific inhibitors. Phenotypic analysis of these clones revealed that: 1) They are resistant to their inducing agents and to their analogs; 2) They remain sensitive to other classes of HCV inhibitors; 3) Resistant phenotype is relatively stable and 4) Resistance is due to adaptation in the viral genome. Sequencing of the entire coding region of resistant clones yielded several consensus mutations. Reverse genetics identified a single mutation located at the very N-terminus of NS3 that is responsible for resistance. We also conducted resistance induction studies with a NS3/4A protease inhibitor, NS5B nucleoside inhibitor and nonnucleoside inhibitor. As expected, resistant clones obtained with protease or polymerase inhibitors are resistant to their inducing agents, but remain sensitive to the compounds in ACH-806 series. Lack of cross resistance between ACH inhibitors and protease or polymerase inhibitors is explained by genotypic analysis of resistant clones.

 

Conclusions:

·        HCV variants resistant to the compounds in ACH-806 series were obtained. These resistant variants carry novel mutation(s) and are not cross- resistant to other classes of HCV inhibitors.

·        ACH-806 is a novel and potent inhibitor of HCV

·        Resistance mutations to ACH-806 are mapped to the very N-terminus of NS3 protein

·        ACH-806 is not cross resistant with other classes of HCV inhibitors

 


LB2. Results of a Phase 1B, Multiple Dose Study of R1626, a Novel Nucleoside Analog Targeting HCV Polymerase in Chronic HCV Genotype 1 Patients.

S. Roberts; G. Cooksley; G. Dore; R. Robson; D. Shaw; H. Berns; M. Brandl; S. Fettner; G. Hill; D. Ipe; K. Klumpp; M. Mannino; E. O'Mara; Y. Tu; C. Washington.

 

Background and Aims:

HCV polymerase, an essential enzyme for HCV replication, is a promising target for the development of compounds to treat HCV infection. R1626, is a prodrug of the nucleoside analog R1479, a potent inhibitor of HCV replication in vitro. This multiple ascending dose study was designed to evaluate the safety, tolerability, pharmacokinetics, and antiviral activity of R1479 in previously untreated patients with chronic HCV genotype-1 infection.

 

Methods:

Patients were treated for 14 days with R1626 and followed up for another 14 days. Assessments included safety, PK, and antiviral activity measured as serum HCV RNA levels.

 

Results:

A total of 47 patients were randomized to oral treatment with 500 mg, 1500 mg, 3000 mg or 4500 mg of R1626 or placebo twice daily. The mean viral concentrations at baseline were ≥ 6.5 log10 IU/mL in all four cohorts. Following oral administration, R1626 was efficiently converted to R1479 with dose proportional pharmacokinetics observed over the entire dose range. Dose and time dependent mean (median) viral concentration decreases of 1.2 (0.8), 2.6 (2.7) and 3.7 (4.1) log10 were observed at 1500, 3000 and 4500 mg, respectively. R1626 was generally well tolerated with increasing adverse events at the highest dose (4500 mg). No viral resistance was found. Reversible mild to moderate hematological changes were observed with increasing doses.

 

Conclusions:

R1626 is a novel nucleoside analog targeting HCV polymerase. These data demonstrate that R1626 is capable of significantly reducing HCV RNA in monotherapy. The decreases in HCV RNA from baseline observed with R1626 are greater than those previously described for HCV polymerase inhibitors and similar to those seen with protease inhibitors. These promising results warrant further investigation of R1626 in combination treatment.

 


LB17. Interim Results from a Randomized, Double-blind, Placebo-controlled Phase 1b Study in Subjects with Chronic HCV after Treatment with GI-5005, a Yeast-Based HCV Immunotherapy Targeting NS3 and Core Proteins.

G. T. Everson; M. J. Tong; I. M. Jacobson; D. M. Jensen; A. A. Haller; G. M. Lauer; J. Parker; J. Ferraro; S. E. Cruickshank; R. C. Duke; D. Apelian; T. C. Rodell; E. R. Schiff

 

Purpose

Tarmogens (targeted molecular immunogens) are whole, heat-killed recombinant S. cereviside yeast engineered to express one or more target protein antigens.  Tarmogens activate both an innate immune response via Toll-like receptors (TLRs), as well as an adaptive, antigen specific cellular immune response.  GI-5005 was engineered to express a hepatitis C virus (HCV) fusion protein comprised of large segments of NS3 protease and Core protein sequences.  These proteins were chosen as targets for ummunotherapy because they are essential for viral replication, contain multiple epitopes that are receognized by both Helper T cells (CD4+) and Killer T cells (CD8+) in acute and chronic HCV infections, and are highly conserved among the different HCV genotypes.   GI-5005, by expressing multiple antigens, was designed to induce a broad cellular immune response, comparable to that which as has been associated with sustained viral clearance in patients acutely exposed to HCV>

 

In preclinical studies, GI5005 has demonstrated:

1.     The ability to induce potent HCV-specific killer T cell and helper T cell responses;

2.     Dose dependency of response, which s boosted with repeat injections;

3.     No evidence of immune neutralization or immune tolerance with repeated injections;

4.     In non-clinical safety studies, GI-5005 and other comparable Tarmogens for infectious disease targets and cancer have been administered to a number of species including mice, rats, rabbits, and non-human primates in both live and heat-killed forms and no significant systemic toxicity has been observed.

 

GI-5005-01 was initiated to evaluate the subcutaneous administration of six dose levels of GI-5005 vs. placebo in subjects with chronic hepatitis C infection who were either partial responders or relapsers to an interferon based regimen using either pegylated or non-pegylated interferon alpha with or without ribavirin, or are treatment naïve due to a contra-indication or refusal to take interferon based therapy.  This is an interim analysis describing the results from 40 patients (0f 72) enrolled in the first four dose-cohorts. 

 

Methods

GI-5005 is whole heat-killed S. cerevisiae yeast harboring HCV NS3 and Core antigens. Subjects with chronic hepatitis C infection who were interferon (IFN) relapsers, partial responders or treatment naïve were eligible. IFN “null responders” and patients with cirrhosis were ineligible. Treatment consisted of 5 weekly subcutaneous (SC) doses of GI-5005 (0.05YU) or placebo over 29 days, followed by two monthly SC doses, and 9 months of post-treatment follow-up. Sequential dose groups of 0.05, 0.5, 2.5, 10YU (1YU=107 yeast) were randomized 3:1 treated:placebo.

Results

 

Safety Summary

There were no serious adverse events, dosing limiting toxicities, or discontinuations due to adverse events.  Related non-serous adverse events were generally limited to transient local injection site tenderness, swelling, and redness consistent with delayed type hypersensitivity, and mild constitutional complaints such as fatigue and low grade fever.

 

HCV RNA

To date in this study, three treated subjects had near-log 10 reductions in viral load (0.75-0.09 log  10 ).  2/3 of these subjects demonstrated positive ELISpot results (profiles 014 and 007 to the left);  testing for the third is ongoing.  No subjects treated with placebo had viral load reductions in this range.  Mean change in serum HCV RNA was comparable between treated and placebo subjects.

 

Hepatic Injury

ALT is well validated measure of hepatic injury and serves as a surrogate for hepatic inflammation.  In prior large hepatitis trials, reductions and/or normalization of ALT levels have been shown to correlate with improved hepatic inflammation and fibrosis as determined by serial biopsy.  In the lowest four dose cohorts, there was a statistically significant difference in maximum ALT reduction (p=0.03) in treated subject versus placebo. 

 

Evaluation of the first 4 cohorts has not revealed a definitive association of response with dose for biochemical as well as immune or viral load endpoints.  Upcoming treatment and evaluation of 20YU and 40YU dose groups will enable further exploration of potential dose response for these key endpoints. 

 

Conclusion

1.     GI-5005 is well tolerated with no SAEs, no DLTs, and no discontinuations due to AEs observed to date. 

2.     GI-5005 converted subjects with a weak cellular immune response typical of chronic HCV patients to a strong cellular immune response with broad HCV epitope coverage, consistent with the immune response seen in patients during the acute stage of infection

3.     The immune responses were observed in association with favourable changes in viral load and ALT:

a.      A statistically significant difference in maximum change in ALT from baseline to all GI-5005 treated subjects compared to placebo treated subjects (p=0.03)

b.     Three treated subjects had viral load reductions approaching 1 log  10 (.075 log 10 –0.09 log 10);  no placebo subjects had HCV RNA reductions >0.065 log10

4.     For immune therapies, HCV viral load reductions may be a trailing indicator of response, following early improvement in biochemical and immune markers.

This research was supported by GlobeImmune, Inc.

 


840. Does coffee drinking protect cirrhotic patients against hepatocellular carcinoma?

G. Pelletier; I. Stucker; G. N'Kontchou; M. Loriot; S. Cenee; M. Gelu-Simeon; F. Degos; P. Beaune; P. Laurent-Puig; J. Trinchet

 

 

Introduction

It has been recently suggested that coffee drinking decreases the risk of chronic liver diseases (Ruhl et al, Gastroenterology 2005). We performed in France a case control study to look for predisposing risk factors of hepatocellular carcinoma (HCC). The data that we present here aimed at analyse the coffee consumption among HCC cases, cirrhosis patients and controls without liver disease.

 

Methods:

The study is an epidemiologic hospital based case control study. Cases (n=134) were newly diagnosed patients as primary HCC developed on cirrhotic liver (alcoholic 62 %, viral 24 %), on the basis of either histology or the presence of focalized lesions detected by any imaging technique, combined with an alpha feto-protein (AFP) level > 250 ng/ml. Cirrhosis (n=122-alcoholic 79 %, viral 15 %) were defined either by histology or by the combination of clinical, laboratory, and endoscopic signs. The absence of HCC was established by the absence of focalized lesions by imaging techniques and by a AFP level < 10 ng/ml. Controls included hospital patients without any liver disorder (n=142).

 

All subjects were male, aged less than 75 years, born in Europe of parents born in Europe. The three groups were matched for age and birth country. HCC and cirrhosis patients were supplementary matched for time since cirrhosis diagnosis. Cases and controls were interviewed with a food frequency questionnaire that included lifetime drinking habits (ie alcohol, soft drinks, coffee, tea consumption). Coffee consumption was categorized as < 1 cup, 1 to 2 cups, > 2 cups/day. Blood samples were collected on EDTA and a DNA bank was established for all subjects.

 

Results:

As shown in the table, we observed a significantly higher coffee consumption among controls without liver disease as compared to HCC cases (p < 0.01), whereas there was no differences between cirrhotic patients with or without HCC. All these associations were adjusted for alcohol consumption considered in drink/day.

 

Conclusion:

Our study confirms that coffee consumption may decrease the risk of chronic liver diseases, but suggests that coffee does not decrease the risk of HCC in cirrhotic patients.

 

Coffee

Controls

Cirrhosis

OR(IC)
vs
controls

HCC

OR(IC) vs controls

0-1

40 %

56 %

1

56 %

1

2

26 %

24 %

0.65
(0.3-1.4

27 %

0.67
(3.3-1.3)

>2

34 %

20 %

0.33
(0.2-0.7)

17 %

0.36
(0.2-0.7)

m + sd

2.4 + 2.1

1.8 + 1.9

 

1.8 + 1.6

 

 


LB23. Rapid and Early Virologic Responses to Peginterferon Alfa-2a plus Ribavirin in Treatment-Naïve Latino vs non-Latino Caucasians Infected with HCV Genotype 1: the LATINO Study.

M. Rodriguez-Torres; V. Ankoma-Sey; M. Y. Sheikh; L. Rossaro; F. M. Hamzeh; L. J. Jeffers; L.

 

Introduction

Latinos have been under-represented in clinical trials of CHC and undertreated in clinical practice. To date, there have been no prospective studies evaluating the response rate of Latino Caucasians to HCV therapy. The LATINO Study was designed to compare the responses of Latino and non-Latino Caucasians infected with HCV genotype 1 to treatment with peginterferon alfa-2a and ribavirin.

 

Methods

This was a prospective, multi-center, open label, comparative, efficacy study designed to treat 267 Latino and 302 non-Latino Caucasian patients infected with HCV genotype 1 and naïve to treatment; the number of cirrhotic patients in each group was 34 (12.7%) Latino group and 29 (9.6%) in the non-Latino Caucasian group.  Country of origin was documented for Latino patients—Mexico (51%), Puerto Rico (32%), Cuba (9%), other (8) and 1% as Mexican and unknown (1%).  Baseline characteristics were generally well matched. The Latino group was slightly younger (45.5±8.83 y vs 48.1±8.31 y) and had slightly higher BMI (29.8±5.69 kg/m2 vs 27.9±5.43 kg/m2), slightly lower mean log [HCV RNA] (6.3±0.05 vs 6.4±0.04).

 

All patients were treated with 180 μg/week peginterferon alfa-2a plus 1000 or 1200 mg/d ribavirin for 48 weeks. HCV RNA was quantified using the Roche High Pure System/COBAS TaqMan HCV Monitor Test, which has a lower limit of detection (10 IU/mL) and a broader linear range for quantification (30-200 million IU/mL) than standard PCR tests. This interim analysis shows rapid virologic response (RVR) and early virologic response (EVR) rates in the two groups of patients.

 

Results

Interim results showed that 195/247 Latinos (78.9%) and 248/279 non-Latinos (88.9%) attained EVR, defined as a ≥2 log [HCV RNA] drop from baseline or undetectable (<10 IU/mL) HCV RNA at Week 12. Undetectable HCV RNA was attained by 35/261 Latinos (13.4%) and 53/293 non-Latinos (18.1%) at Week 4 and by 121/247 (49.0%) and 182/279 (62.5%), respectively, at Week 12. Through Week 12, 5 Latinos (1.9%) and 12 non-Latinos (4.0%) withdrew due to adverse events, and 15 (5.6%) and 13 (4.3%), respectively, withdrew for non-safety reasons.

 

Conclusion

The interim results showed that RVR and EVR rates were higher in non-Latino Caucasians than in Latino Caucasians. Combination therapy was safe in both populations. This ongoing trial will show if this trend holds over the long term and if SVR rates differ.

 


LB20. Retrospective Analysis of Alanine Aminotransferase Elevations in Patients Receiving the Maximum Recommended Daily Dose of Acetaminophen Shows Elevations Are Low, Transient, and Clinically Insignificant. 

E. K. Kuffner; A. R. Temple; K. M. Cooper; J. S. Baggish; D. L. Parenti

 

Background:

In some osteoarthritis studies where acetaminophen (APAP) was administered over multiple days, low-level alanine aminotransferase (ALT) elevations have occasionally been reported.

 

Objective:

To retrospectively analyze ALT data from McNeil-sponsored osteoarthritis clinical studies to assess the frequency and magnitude of ALT elevations and the rate of ALT resolution while continuing treatment with the maximum recommended daily dose of APAP.

 

Methods:

Nine controlled osteoarthritis clinical trials were identified in which APAP alone was administered in at least 1 treatment group. Baseline and on-treatment ALT values were measured in 7 studies. Patients receiving the maximum recommended daily dose of APAP (3900 or 4000 mg/day) for 4 weeks to up to 12 months were included.

 

Results:

No patient treated with the maximum recommended daily dose of APAP developed hepatotoxicity or hepatic failure. In the 7 studies, 892 patients had baseline transaminase activity at or below the upper limit of the reference range (ULRR), had an on-treatment ALT measurement, and received the maximum recommended daily dose of APAP. While taking the maximum recommended daily dose, 733 (82.2%) of 892 patients never had an ALT above ULRR.

 

Of the 892 patients, 42 (4.7%) had an on-treatment ALT >1.5 times ULRR (Table). A subsequent ALT value following the elevation was available for 29 of these 42 patients. Documented resolution or a decreasing ALT while continuing APAP treatment was noted for 27 patients (93.1%). No patient had an on-treatment ALT >3 times ULRR in conjunction with hyperbilirubinemia. No patient had an ALT >10 times ULRR. An ALT above ULRR was not associated with an increased frequency of symptoms potentially related to a hepatic origin.

 

Conclusions:

This analysis involving 892 patients treated with 3900–4000 mg/day of APAP shows that83% never had an ALT>ULRR.  Low-level, transient ALT elevations were reported in 17.8% of patients and usually resolve or decrease with continued APAP treatment, are unaccompanied by signs or symptoms of liver injury, and, as such, appear to be clinically insignificant.

 

No patients treated with the maximum recommended dose of APAP developed an ALT>3 x ULRR in conjunction with hyperbilirubinemia.  The maximum recommended daily dose of APAP did not cause liver failure or dysfunction even when use for 12 months.   When used at recommended doses, APAP remains a safe first-choice treatment for OA.

Table. Number (%) of Osteoarthritis Patients With or Without an ALT Value >ULRR During Treatment With the Maximum Recommended Daily Dose of APAP for 4 Weeks to 12 Months

 

 

Total
≤ULRR

Total
>ULRR

>1.5 × ULRR

>3 × ULRR

>5 × ULRR

>10 × ULRR

n
(%)

733
(82.2)

159
(17.8)

42
(4.7)

10
(1.1)

4
(0.4)

0
(0)

 

 

 


LB9. Sustained Virologic Response Is Associated with Eradication of Hepatitis C Virus and Fibrosis Regression in Patients Treated for Chronic Hepatitis C.

S. Maylin; M. Martinot -Peignoux; N. Boyer; M. Ripault; D. Cazals-Hatem; N. Giuily; C. Castelnau; C. Féray; M. Nicolas-Chanoine; P. Bedossa; P. Marcellin

 

Background:

It is unclear whether hepatitis C virus (HCV) is eradicated in patients with chronic hepatitis C who achieve a sustained virologic response [SVR). During this long-term follow-up study, HCV-RNA was measured in serum, liver, and peripheral blood mononuclear cells [PBMCs) in patients with chronic hepatitis C who had a SVR and in whom liver histology was assessed.

 

Patients/Methods:

345 patients with SVR after treatment were studied. SVR was defined by the absence of detectable serum HCV-RNA 6 months after treatment cessation. 242 (70%) patients received PEG-IFN plus ribavirin therapy (215 PEG-IFN alpha 2b and 27 PEG-IFN alpha 2a). HCV-RNA was tested: -(1) in serum for all the 345 patients every years and at the time of PBMCs and/or liver tissue collection, -(2) in PBMCs collected in 159 patients 3.9±3.4 (0.5-18) years after treatment, -(3) in liver tissue in 116 patients, (32 at the end of treatment, 32 six months after treatment cessation and 52 at 3.9±3.4 (1-14) years post treatment. Both PBMCs and liver tissue were available in 60 patients. Serum, liver tissue samples and PBMCs were kept frozen at -80°C until use. HCV-RNA was detected with VERSANT HCV-RNA Qualitative assay (Qual TMA, Bayer Healthcare, LLc, Tarrytown, N.Y. USA) (sensitivity 10 IU/ml). We assessed the TMA sensitivity using 3 WHO standard dilutions tested 10 times. 100%, 100% and 60 % of the WHO dilutions set at 5 IU/ml, 2.5 IUml and 1 IU/ml were detected with TMA.

 

Results:

Patients were followed up for a mean of 4.0±3.01 (range, 0.5 -18) years. Serum HCV RNA remained undetectable in all the patients (1624 samples). Normal serum ALT levels were maintained in most of the patients; HCV-RNA was detectable in the PBMCs for 2 patient (3 years after treatment cessation), and in the liver tissues for 2 patients, (1 at 1 year; 1 at 6 years). The 2 patients with detectable HCV-RNA in liver tissue had available PBMCs with undetectable HCV-RNA. Pre and post-treatment liver biopsy specimens were available for 126 patients. Fibrosis stage was improved in 56%, stable 32% and deteriorated in 12%. Regression of cirrhosis was observed in 9 out of 14 patients. No cirrhosis decompensation was observed.

 

Conclusion:

·        These data are some of the longest follow-up data available (up to 18 years after treatment cessation) in patients successfully treated fro chronic hepatitis C.

·        None of the 345 patients in this study had a late relapse

·        210 (98.6%) of 213 patients had undetectable HCV RNA in PBMCs or liver tissue, determined by the sensitive TMA assay.

·        These results confirm observations from our earlier study:  clearance of serum HCV RNA is durable and associated with undetectable hepatic HCV RNA and market histologic improvement.

·        Our data show the importance of using a very sensitive assay (TMA) to assess SVR.

·        Risk for hepatocellular carcinoma remained in patients who attain an SVR, underscoring the need for continue surveillance of this cohort if cirrhosis persists.

·        These results support the hypothesis that HCV is eradicated in patients who attain an SVR after receiving IFN-based therapy.

 

1147. An Open Label, Comparative, Multicenter Study of Peginterferon Alfa-2a plus Ribavirin in the Treatment of Patients with Chronic Hepatitis C/Hepatitis B Co-Infection versus those with Monoinfected Chronic Hepatitis C: An Interim Report. 

C. Liu; P. Chen; J. Kao; M. Lai; C. Chen; C. Liu; M. Yu; C. Dai; Z. Lin; W. Chuang; S. Lu; J. Wang; T. Hu; C. Hung; C. Lee; W. Su; S. Wu; C. Lin; L. Liao; H. Kuo; H. Tung; Y. Chao; S. Tung; S. Yang; D. Chen.

 

Introduction:

Pilot studies using standard interferon in combination with ribavirin for 6 months to treat patients with dual chronic hepatitis C and B infection have shown that a sustained hepatitis C virus (HCV) clearance rate could be achieved to an extent comparable to that observed in HCV monoinfected patients. We have therefore conducted a multicenter clinical trial using peginterferon-based combination therapy in Taiwan.

 

Patients and Methods:

Eligible patients with active HCV (serum ALT level >=1.5X ULN and HCV RNA >=100,000 copies/mL), with (n=161) or without (n=160) co-existence of hepatitis B surface antigen, were consecutively enrolled. Patients infected with HCV genotype 1 received 48 weeks of combination therapy with peginterferon alfa-2a 180 mcg weekly plus daily 1000-1200 mg ribavirin. Patients with HCV genotype non-1 received 24 weeks of combination therapy with peginterferon alfa-2a 180 mcg weekly plus daily 800 mg ribavirin. The primary efficacy endpoint was sustained HCV RNA clearance at 24 weeks post-treatment.

 

Results:

Patients were recruited and enrolled between June 2004 and end of February 2006.  Here we present the interim results updated in October 2006 (table).

 

Summary

·        A sustained HCV clearance rate of 59% was achieved in the most difficult-to-treat patients with genotype 1 HCV/HBV dual infection, 24 weeks post-treatment

·        In HCV genotype non-1 dually infected patients, HCV clearance (81%) was achieved to an extent comparable to that observed in HCV monoinfected patients (77 % and 79% for genotype 1 and non-1 patients respectively)

·        In general there was little difference between response rates for genotype 1 and non-1 patients or at the end of treatment and f24 weeks post-treatment.

 

Conclusions:

Combination therapy using peginterferon alfa-2a with ribavirin appears safe for patients dually infected with HCV and HBV.  Final results will be available at the end of 2007. 

 

Table 1: HCV RNA clearance at the end of treatment (EOT) and at 24 weeks post-treatment (SVR)

 

Dual Hepatitis B and C

HCV monoinfection

HCV genotype

1

Non-1

1

Non-1

Pts Enrolled (n)

97

64

110

50

Pts withdrawn (n/%)

11 (11.3)

4 (6.3)

8 (7.3)

2 (4.0)

Pts(n/%) Completing treatment/follow-up

 

30 (30.9)

 

40 (62.5)

 

90 (7.3)

 

2 (4.0)

 

HCV EOT response* (%)

 

68

 

86

 

87

 

91

HCV SVR (%)

62

85

80

81